Galvanic vestibular stimulation system and method of use for simulation, directional cueing, and alleviating motion-related sickness

ABSTRACT

The present invention relates to systems and techniques for stimulating a user. For example, materials and methods for manipulating nystagmus and the related vestibular system with coupling of galvanic vestibular stimulation (GVS) and visual cueing are provided herein. Use of GVS within the present invention may be applied to simulation, alleviating motion sickness, and directional cueing of a user to a precise target location.

RELATED APPLICATIONS

This application is a divisional application which claims the benefit ofand priority to U.S. patent application Ser. No. 12/660,768 filed onMar. 4, 2010, which claims the benefit of and priority to U.S.Provisional Application Ser. No. 61/209,262 filed on Mar. 5, 2009 under35 U.S.C. §§119, 120, 363, 365, and 37 C.F.R. §1.55 and §1.78.

GOVERNMENT RIGHTS

This invention was made with government support under Nos.N00014-06-M-0209, N68335-07-C-0443, and N68335-08-C-0294 awarded by theNavy. The government has certain rights in the invention.

FIELD OF THE INVENTION

The present invention relates to systems and techniques for simulatingmotion to a human subject, alleviating motion sickness, and directionalcueing and more particularly, relates to manipulating nystagmus and therelated vestibular system with coupling of galvanic vestibularstimulation (GVS).

BACKGROUND OF THE INVENTION

Acceleration of the head evokes responses from the vestibular receptorsin order to compensate for head motion. This is referred to as thevestibular ocular reflex (VOR). Under normal conditions, the VOR canallow an individual to maintain visual fixation during head movement, byensuring that for every movement of the head, there is an equal andopposite compensatory movement of the eyes. Stimulation of thevestibular receptors in the semi-circular canals can result from angularhead acceleration and from stimulation of the otolith organs from linearacceleration (i.e. gravity, head tilt, and centrifugal force). Thesesignals can activate the central nervous system through reflexes thatevoke changes in the extra-ocular muscles, the visual system, andposture, enhancing acuity during head rotation and balance duringchanges in body position. The semicircular canals, and the signals theysend to the brain, function as yoked pairs. In the absence of headmotion, a train of pulses is sent from each side of the head. As thehead experiences acceleration (other than gravity), the pulse train onone side of the head increases in frequency while on the other side itdecreases. Our brains have adapted to interpret this differential signalas acceleration. When the central nervous system cannot balance theexcitatory and inhibitory inputs from the semi-circular canals andotolith organs, the individual can experience an illusion of motionand/or loss of balance.

There has been various research into the use of galvanic vestibularstimulation in terms of simulators, directional cueing, and alleviatingsymptoms of motion sickness, however, there are still many neededimprovements to the current technology. In particular, there is a needfor a simulator system that gives a user a more realistic view ofdriving a vehicle such as a boat, airplane, automobile, and the like.For example, even flight simulators that use a motion platform arelimited in the amount and type of motions they can impart to the user.There has also been some work in the use of GVS to alleviate feelings ofmotion sickness. However, the current systems use AC current to overridethe natural brain signals that cause a person to feel sick. Thisoverriding requires more electrical energy being provided to a user. Theuse of more electrical energy can be a safety concern to a user.Therefore, there is a need for GVS technology that uses less externalelectrical energy on a person. Additionally, GVS technology has beenapplied to users causing them to physically move side to side. However,there is a need to develop this technology to be more precise andaccurate as well as be able to move a person in many differentdirections, including forward and backward. For example, it would beadvantageous to the public to be able to precisely direct a person or agroup of people to a specific distinct location with the use of GVStechnology.

SUMMARY OF THE INVENTION

The present invention relates to systems and techniques for astimulation process. For example, materials and methods for manipulatingnystagmus and the related vestibular system with coupling of galvanicvestibular stimulation (GVS), orientation sensors, and visual inputs areprovided. For example, materials and methods for simulating rotationalmovement (e.g., roll, pitch and yaw) are provided. For example, methodsfeaturing a combination of stimulations for isolating perceivedrotations and directions are provided. For example, a galvanicvestibular stimulator featuring surface electrodes, and methods forenhancing and mitigating motion perception are provided.

Such use of GVS may be employed in a variety of environments where theGVS is used to accentuate or decrease motion that is otherwiseexperienced by a human subject—to attempt to match (or perhaps evenmismatch) ocular clues and vestibular clues for the subject. Forexample, a subject who is perceiving motion in a flightsimulator—whether from moving images projected by the simulator oractual motion of a set or other platform on which the subject ismounted—may sometimes suffer from simulator sickness. GVS may be used todecrease both the incidence and severity of nausea and dizziness that asubject might otherwise experience in such a situation (sometimes knownas “simulator sickness”), and thus permit more rewarding and lengthiertraining. The present invention could also allow subjects to avoidlimitations on flying immediately following a simulator training sessiondue to motion sickness. Therefore, the present invention would allow fora subject to go through a simulator training session without gettingsick and then fly the real mission immediately after the simulator. Thisenables the most recent information to be used in the creation of themission simulation. Similarly, electronic GVS may be coordinated withmotion sensed in an actual vehicle such as an airplane, to decrease theincidence and severity of motion sickness. GVS may also be used toaugment a subject's other perceptions of motion, such as in aprofessional flight simulator or video game, where a game controller mayprovide inputs about the subject's motion in the game to a GVScontroller, which may in turn provide stimulation to the subject so thatthe subject perceives physical motion that matches, at least to someextent, the visual motion they are seeing on their screen or screens.

The GVS system may be exemplified as a motion simulation system having acomputer receiving inputs corresponding to a sensed motion experiencedby a subject. The system also includes an electronic stimulationdetermination module that is connected to the computer for determining alevel of electrical stimulation to be provided to the human subject tocreate non-visual perceived motion in the subject corresponding with themotion experienced by the subject as received by the computer. Also, thesystem has an electrical stimulator connected to the electronicstimulation determination module for generating electrical signalsthrough the electrodes to create in the subject a sensation of motionmatched to the sensed motion experienced by the human subject. Thesystem further includes at least three distinct sets of electrodesconnected to the electrical stimulator. The electrodes are located onthe human subject. Stimulation passes between at least two electrodes ofeach distinct set. These three distinct sets of electrodes maypreferably include an electrode on the subject's forehead, an electrodeon the subject's mastoid, an electrode on the subject's alternativemastoid, and an electrode on the subject's back of the neck.

There is also a computer-implemented method of simulating motion in asubject's perception which includes receiving an indication of a sensedmotion experienced by the subject, determining a level of motion-relatedstimulation needed to match the subject's response to the sensed motionexperienced by the subject, and delivering electrical signals to atleast three distinct sets of electrodes placed in contact with thesubject to provide the subject with a non-visual perception of motion inat least three separate directions that are coordinated with the sensedmotion experienced by the subject.

A computer-implemented method of providing directional cueing includesreceiving an indication of the direction and speed of the motion of ahuman subject, determining the course needed to direct the subject to adesired location. The course includes one or more movements needed tomove the subject to the desired location. Another step in the process isdetermining a level of stimulation needed to suggest to the subject themovements needed to achieve the course to the desired location. Thelevel of stimulation correlates with a desired direction and speed thatis input for each needed movement within the course. The method furtherincludes delivering electrical signals to at least two distinct sets ofelectrodes placed in contact with the human subject to cause the subjectto move along the course to the desired location.

There is also a system for providing directional cueing including acomputer that receives motion inputs corresponding to a location andmovement of a human subject. The motion input includes a measurement ofdirection and speed. The system also has an electronic stimulationdetermination module connected to the computer for determining a levelof electrical stimulation to be provided to the subject in order todirect the subject on a course to a desired location. This courseincludes one or more direction and speed components. The system furtherincludes an electrical stimulator connected to the electronicstimulation determination module for generating electrical signals tocause the subject to move in one or more directions and at a speedmatching the course to the desired location. The subject stimulatorstops generating electrical signals when the subject reaches the desiredlocation. There are also at least two distinct sets of electrodesconnected to the electrical stimulator. These electrodes are located onthe human subject causing stimulation from the electronic stimulator topass between at least two electrodes of each distinct set.

Unless otherwise defined, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which this invention pertains. Although systems andtechniques similar or equivalent to those described herein can be usedto practice the invention, suitable systems and techniques are describedbelow. All publications, patent applications, patents, and otherreferences mentioned herein are incorporated by reference in theirentirety. In case of conflict, the present specification, includingdefinitions, will control. In addition, the materials, methods, andexamples are illustrative only and not intended to be limiting.

The details of one or more embodiments are set forth in the accompanyingdrawings and the description below. Other features, objects, andadvantages will be apparent from the description and drawings, and fromthe claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a depiction of the electrode placement for variousstimulation embodiments of the present invention as shown from the topof the subject's head.

FIGS. 1B and 1C are depictions of two embodiments of the presentinvention including electrodes used in three distinct sets.

FIG. 1D is a depiction of two non-distinct sets of electrodes.

FIG. 2A is a three dimensional view of the coronal 110 and sagittal 112planes intersecting the head.

FIGS. 2B and 2C are depictions of electrodes 201, 202, 203, 204, and aneutral electrode 205 placed on the coronal 111 and sagittal 113 lines.

FIG. 3 is a depiction of perceived motion in response to directedstimulation of electrode sets.

FIGS. 4A and 4B are plots of eye velocity (degrees/second) over timerepresenting nystagmus due to subject rotation. FIG. 4A is the plot ofeye velocity without GVS (no electric stimulation). FIG. 4B is the plotof eye velocity with simultaneous GVS.

FIG. 5 is a depiction of an example subject's response to rampstimulation protocol displayed in visual analog scales.

FIG. 6 is a plot of averaged recorded values from a group of subjects'visual analog scales versus ramp-up time at 0, 300, and 600 msec.

FIG. 7 is a representative plot showing relationship between stimulationcurrent (mA) between one set of electrodes and perceived rotations abouteach axis.

FIG. 8 is a schematic block diagram of a motion stimulation system.

FIG. 9 is a flowchart showing a method of using motion stimulation on asubject.

FIG. 10A is a graph of the average observed scores of sickness symptomsthat resulted from simulator tests with GVS and without GVS (sham).

FIG. 10B is a graph of the average self-reported scores of sicknesssymptoms that resulted from simulator tests with GVS and without GVS(sham).

FIG. 10C is a graphical comparison of all the subjects' self reportedscores regarding the symptom of nausea without GVS (sham) and with GVS.

FIG. 11 is a schematic block diagram of one embodiment of the presentinvention including electronic components.

DETAILED DESCRIPTION OF THE INVENTION

This document relates to systems and techniques for a stimulationsystem. For example, materials and methods for manipulating nystagmusand the related vestibular system with coupling of galvanic vestibularstimulation (GVS), accelerometers, and visual inputs are provided. Forexample, battery operated galvanic vestibular stimulators featuringsurface electrodes, and methods for simulating motion in a subject areprovided.

GVS systems and methods described herein can be used to affect motioncues. Motions involved in the present systems and methods may be linear,rotational and a combination of linear and rotational. Linear motionsare movement vertically, forward/backward, and left/right. Rotationalmotions include a yaw angle, pitch angle, and roll angle. Yaw isrotation about the z-axis, pitch is rotation about the y-axis, and rollis rotation about the x-axis. For example, a GVS system described hereincan be used to simulate the right roll to about 90 degrees or greater,left roll to about 90 degrees or greater, positive pitch to about 90degrees or greater, negative pitch to about 90 degrees or greater, rightyaw to about 360 degrees or greater, and left yaw to about 360 degreesor greater. In some cases, pure pitch, roll, and yaw can be simulated.In some cases, a combination of pitch, roll, and yaw can be simulated.In some cases, the materials and methods described herein can enhance asubject's sensation of motion in combination with actual motion. Forexample, enhanced perception of rotational acceleration can bestimulated while a subject is rotating in a rotational chair. In somecases, the materials and methods described herein can be used tomitigate spatial disorientation. For example, a diminished sensation ofmotion can be stimulated. In some cases, the materials and methodsdescribed herein can be used to create spatial disorientation in asimulator for training purposes. In some cases, the materials andmethods described herein can be used to mitigate motion sickness orsimulator sickness. In some cases, the materials and methods describedherein can be used for directional cueing. For example, sensationsassociated with turning or stopping can be provided to an ambulatorysubject.

GVS systems and methods described herein include at least two electrodesfor stimulating a subject's vestibular system. Two or more electrodesmay also be used. FIG. 1A depicts a group of possible embodiments of thepresent invention with a top view of a subject's head 100 showing thenose 102 and ears 103 with four active electrodes. The four possibleactive electrodes in FIG. 1 are positioned: at the subject's leftmastoid 201, at the subject's forehead 202, at the subject's rightmastoid 203 and at the subject's neck 204. The direction of stimulationbetween each set of electrodes is indicated: between the electrodes atthe left mastoid and forehead (212), between the electrodes at theforehead and right mastoid (223), between the electrodes at the left andright mastoid (213), between the electrodes at the right mastoid and theneck (234), between the electrodes at the left mastoid and neck (214),and between the electrodes at the forehead and the neck (224). Otherelectrode arrangements may also be made.

For example, a GVS system described herein can have one electrodeattached on the forehead, one electrode on the left high mastoid, oneelectrode on the left low mastoid, and one on the nape of neck. In somecases, a GVS system described herein can have one electrode on the righthigh mastoid, one electrode on the right low mastoid, one electrode onthe left high mastoid, and one electrode on the left low mastoid. Insome cases, a GVS system can include a grounding electrode, which can beplaced at any suitable position for safety, such as the nape of theneck, for example. In some cases, a GVS system can feature electrodesintegrated into a device, such as a headband or helmet.

The embodiments of the present simulator may include at least twodistinct sets of active electrodes more preferably three or moredistinct sets of active electrodes. For example in FIG. 1B, a first setmay be a forehead electrode to the left mastoid electrode (212), asecond set may be the left mastoid electrode to the right mastoidelectrode (213), and a third set may be the right mastoid electrode to aneck electrode (234). For example in FIG. IC, a first set may be aforehead electrode to the left mastoid electrode (212), a second set maybe the left mastoid electrode to the right mastoid electrode (213), anda third set may be the left mastoid electrode to a neck electrode (214).In FIG. 1D, the electrode set of the forehead and left mastoid (212) andthe electrode set of the forehead and right mastoid (223) aresymmetrical and not considered distinct. FIG. 1D displays a subjectusing a GVS system that results in only one distinct set of electrodes.The stimulation between symmetrical sets 212 and 223 results insimulated motion in the same plane, therefore, the electrode sets201-202 and 202-203 are not considered distinct from one another.

The present invention is further exemplified within the embodimentsshown in FIGS. 2A-2C. An isometric view of a subject's head is shown inFIG. 2A showing the sagittal plane 112 and coronal plane 110 bisecting auser's head. The lines of the planes bisecting the user's head are shownas the sagittal line 113 and the coronal line 111. In FIGS. 2B and 2C,one embodiment includes a subject's head with electrode 201 positionedat the subject's left high mastoid along the coronal line 111, electrode203 positioned at the subject's right high mastoid along the coronalline 111, electrode 202 positioned at the subject's forehead along thesagittal line 113, and electrode 204 and neutral electrode 205 arepositioned at the subject's nape of neck along the sagittal line 113.

Simulation of motion in roll, pitch, and yaw can be accomplished bydirectional stimulation between electrode sets or a combination ofelectrode sets. All relevant electrodes may be stimulated simultaneouslyin order to achieve simulation of motion. Directional stimulation allowsfor stimulation to pass in either direction between two electrodeswithin a set. In order for stimulation to pass in one direction oranother, a first electrode within a set is commanded to absorb current(anode) while a second electrode within the set is commanded to emitcurrent (cathode). Therefore, stimulation will directionally flow fromthe second electrode to the first electrode. For example, a motion thatis mainly roll left may be simulated by stimulating electrodes at theright mastoid (anode) and the nape of the neck (cathode) causing currentto flow in the direction from the neck to the right mastoid. Forexample, a motion that is mainly a roll right and pitch backward may besimulated by stimulating electrodes at the forehead (anode) and theright high mastoid (cathode) causing current to flow in the directionfrom the right high mastoid towards the forehead. For example, a motionthat is mainly yaw right can be simulated by stimulating electrodes atthe right high mastoid (anode) and left high mastoid (cathode) causingcurrent to flow in the direction from left high mastoid to right highmastoid. In some cases, pure pitch can be simulated by using acombination of stimulations, such as by stimulating electrodes at theforehead and the right mastoid (roll left and pitch forward), incombination with stimulating electrodes at the left high mastoid and thenape of the neck (roll right).

GVS systems and methods described herein may use AC current orpreferably near DC current and use a maximum stimulation of about 2.5mA. In some cases, a stimulation dose can be from about 1 mA to about2.5 mA. For example, a stimulation dose can be about 1, 1.5, 2.0, and2.5 mA. In some cases, maximum stimulation can be applied without anytime delay and with greater than 2.5 mA of current. In some cases,stimulation can be ramped up to the maximum stimulation current over aperiod of time. For example, stimulation can be ramped up from about 0ms to about 600 msec. For example, stimulation can be ramped up in about25, 75, 175, 300, or 600 msec. In some cases, stimulation can beterminated immediately after the response has been achieved. In somecases, stimulation can be ramped down. For example, stimulation can beramped down from about 0 ms to about 600 msec. For example, stimulationcan be ramped down over 25, 75, 175, 300, or 600 msec.

In one embodiment, a low-level DC signal may be used which may bepositive at one stimulation point and negative at another stimulationpoint on the head to naturally alter the train of pulses. The positivesignal serves to depolarize the cells causing a decrease in theireffective latency period, while the negative signal has the oppositeeffect. Current-limited stimulation may be used, whereas the maximumcurrent between any set of electrodes is kept at 2.5 mA for certainimplementations. For example, FIG. 3 shows examples of a human subject100 in three different states, with vestibular activation patternssuperimposed over each state. The first state shows equilibrium for thesubject, with equal activation levels on both sides of the head (104,105), while the second state shows the natural vestibular activationsignals induced in the subject when they tilt their head (106, 107). Thethird state shows a perception of tilt or motion that is induced in thesubject by unequal GVS stimulation at two different points on the head.This third state may be induced with any variation of electrode sets asshown in FIGS. 1A-C while preferably having at least 3 distinct sets.The vestibular signals in the third state (108, 109) are similar tothose in the second state (106, 107). In the second state (head tilt),train of pulses on one side of the subject's head slow down while thetrain of pulses speed up on the other side. In order to change the trainof pulses, stimulations include an increase/decrease of voltage andcurrent applied to the subject. By increasing/decreasing voltage andcurrent, the train of pulses can be sped up or slowed down to match aspecific movement. In the third state, both voltage and current wereapplied unequally at two different points on the subject's head causinga change in the vestibular signal from equilibrium (104, 105) to a thirdstate (108, 109). Therefore, the application of GVS (third state)induced this same effect to the subject without tilting the head.

Feedback mechanisms from the subject can also be combined with othermechanisms discussed here. For example, a subject can be subjected tovisual motion (e.g., via a simulator or videogame background beingdisplayed in motion before the subject), perceived motion (e.g., via GVSstimulation), and real non-visual motion (e.g., via a seat or otherplatform such as a vehicle on which the subject is positioned), or anycombination of the three. The subject may provide feedback regardingtheir total perception of motion using a joystick. In addition, thesubject may be provided with additional input mechanisms such asjoysticks to control the level of perceived motion, such as a controlstick for a simulator or a D-pad for a videogame, and they couldalternatively or simultaneously provide input on a different joystickregarding the level of perceived motion that they created by their owninput to the simulator or video game system.

The invention will be further described in the following examples, whichdo not limit the scope of the invention described in the claims.

EXAMPLES Example 1 Enhancing Motion Perception Using VestibularStimulation

Electrodes were attached to the subject, as shown in FIGS. 2B and 2C. Asshown in FIGS. 2A-C, electrodes may be placed along the sagittal andcoronal planes (112 and 110 respectively). Placement along the sagittaland coronal planes allows for more accurate/precise inducement ofperceived motion on a subject. Along the coronal plane line 111, one ormore electrodes may be placed along the mastoid. Along the sagittalplane line 113, one or more electrodes may be placed on the centerlineof the forehead or on the back of the neck. Electrodes may be positionedas follows: one electrode on left high mastoid 201, forehead 202, righthigh mastoid 203 and nape of neck 204. A grounding electrode (neutral)205 may be positioned on the neck. The grounding electrode 205 is notactive and is present as a safety precaution for absorbing any leftovercurrent in a subject's head.

In a first test, a subject was seated in a rotary chair and rotated at afixed velocity (first to one side and then to the other) without anyelectrical stimulation. Nystagmus was determined by monitoring eyevelocity. In the second test, the subject was once again rotated butwith an added vestibular stimulation of motion in the yaw direction(simulate yaw) by stimulating electrode sets as shown in FIG. 1B. Theyaw direction is the same as spinning in a rotary chair which is turningabout the vertical axis. Stimulating a subject in a yaw directionamplifies the actual movement in the rotary chair. FIGS. 4A and 4Bdisplay plots of eye velocity (degrees/second) over time representingnystagmus due to subject rotation. The dashed line in these figuresrepresents chair velocity. In FIG. 4A, there was no electric stimulationused on the subject while being rotated in the chair. FIG. 4B displaysthe impact to a subject's eye velocity with added GVS stimulation. Thecomparison of these graphs describes the impact that vestibularstimulation can have on a subject's sensation of motion. In FIG. 4B andTable 1, the results show enhanced eye velocity consistent with thegreater perceived rotational speed. These results demonstrate enhancedsensation of motion with GVS.

TABLE 1 Eye velocity Chair (degrees/second) angular velocity With GVS =Percentage increase (degrees/ 2.5 mA * sign due to vestibular second)Without GVS (chair_speed) stimulation 60 21 29 38% −60 16 22 38%

Example 2 Stimulation Ramps

The stimulation methods described in this example may be based onnear-DC values. Achieving the desired stimulation level can beaccomplished in a number of ways, including with ramp-ups andramp-downs. Table 2 summarizes example stimulation scripts tested. Datawas collected from 7 subjects as described above, except thatstimulations included different ramp-up or ramp-up and ramp-down times.

TABLE 2 Ramp-up and Ramp-down Ramp-up stimulation stimulation

Values for ‘a’ Values for ‘a’ and ‘c’  0 ms  0 ms  25 ms  25 ms  75 ms 75 ms 175 ms 175 ms 300 ms 300 ms 600 ms 600 msFIG. 5 shows a typical response to the ramp stimulation protocoldisplayed in visual analog scales. FIG. 6 shows data for all 7 subjects(plots averaged recorded values from subjects' visual analog scalesversus ramp-up times). This data indicates that the sensation at theskin decreased with longer ramp-up times with some variability betweensubjects.

Example 3 Dose Response Tests

Data Collection

Subjects were seated in a rotary chair with electrode placement asindicated above. Current was applied simultaneously to positive andnegative electrodes within each set, without visual input required, toinduce a feeling of a desired rotation. To quantify the dose response inall three axes of rotation, each subject underwent thirty protocolslasting 20 seconds. The protocols utilized ten different combinations ofelectrode stimulation sets (Table 3) to quantify the dose response inall three axes of rotation. Prior to testing, the script order wasrandomized for each subject. Perception data was collected from eachsubject via an avatar program. Subjects were provided with a wirelessjoystick for reporting sensed motion. Data was collected from 21subjects.

TABLE 3 Test Group 1: Test Group 2: Test Group 3: ±1.5 mA ±2.0 mA ±2.5mA Perceived Script Positive Negative Script Positive Negative ScriptPositive Negative Motion No. Electrode Electrode No. Electrode ElectrodeNo. Electrode Electrode Roll right 1 #201 #202 11 #201 #202 21 #201 #202Pitch backward Roll right 2 #202 #201 12 #202 #201 22 #202 #201 Pitchforward Roll right 3 #202 #203 13 #202 #203 23 #202 #203 Pitch backwardRoll left 4 #203 #202 14 #203 #202 24 #203 #202 Pitch forward Roll left5 #203 #204 15 #203 #204 25 #203 #204 Roll right 6 #204 #203 16 #204#203 26 #204 #203 Roll right 7 #204 #201 17 #204 #201 27 #204 #201 Rollleft 8 #201 #204 18 #201 #204 28 #201 #204 Yaw left 9 #201 #203 19 #201#203 29 #201 #203 Yaw right 10 #203 #201 20 #203 #201 30 #203 #201

Data was recorded as the three inclination angles of the avatar aboutthe x-axis (pitch, reported as ±180 degrees), y-axis (roll, reported as±90 degrees), and z-axis (yaw, reported as ±180 degrees) respectively.FIG. 7 shows a typical plot of the data obtained from the dose-responsetest. Each curve represents the perceived rotations between electrodes201 and 203 for each axis (x, y, z) over a stimulation period of 20seconds. There was very little perceived rotation about the x-axis inthis example, but quite a bit about each of the y- and z-axes for thisstimulation. In all cases, the perceived rotation (R) was zero for nostimulation (S). A basic relationship between the perceived rotationsabout the three axes (R_(x), R_(y), and R_(z)) and the directions ofstimulation was obtained by performing a curve fit through these dataplots. In one embodiment (for example FIG. IC), electrodes are numbered1 through 4 and the electrode sets are labeled S₁₂, S₁₃, and S₁₄.Electrode 1 is 201, electrode 2 is 202, electrode 3 is 203, andelectrode 4 is 204 as shown in the figures. By placing a higher voltageat electrode 1 compared with electrode 2, it causes current to flow fromelectrode 1 to electrode 2. This creates a positive S₁₂. However, otherembodiments that include other combinations of electrodes may bepossible such as S₂₃, S₁₃, S₁₄, S₁₂, S₃₁, S₁₄, and so forth.

Stimulation from electrode 2 to 3 resulted in an equal but oppositeeffect to stimulation from electrode 2 to 1. Conversely, stimulationfrom electrode 3 to 2 resulted in an equal effect to stimulation fromelectrode 2 to 1. Results of stimulation from electrode 3 to 2 and from2 to 1 were averaged (S₃₂₁, stimulation either from electrode 3 to 2 orfrom 2 to 1). The situation was identical for stimulations from 1 to 4and from 4 to 3, so data was collected into a single value S₁₄₃.

During testing and to maintain a control, some subjects may bestimulated with GVS while other subjects were not stimulated with GVS.Stimulated subjects may experience a localized sensation such as slighttingling or potentially mild tingling. Thus, non-stimulated subjects maybe given a small “sham” stimulation, e.g., 1 mA current appliedbilaterally such as behind the ears, so as to make the subject believethat they are receiving GVS.

Data Analysis

A set of three equations can be used to describe the relationship ofinputs (S) to output rotations (R): Rotation in x, y, or z (roll, pitch,and yaw) is given by:R _(x) =AS ₁₃ +BS ₃₂₁ +CS ₁₄₃R _(y) =DS ₁₃ +ES ₃₂₁ +FS ₁₄₃ R=f(S)R _(z) =GS ₁₃ +HS ₃₂₁ +IS ₁₄₃Note that in these equations, the values R are for perceived rotationswhich may be in degrees/second, radians per hour, or the like and thevalues S are stimulations in milliamps (mA), Amps, or the like. Eachletter (A through I) represents a time-varying value in the matrix thatrelates input S to output R. For subjects looking forward, the perceivedrotation was in line with simulator axes. For a subject lookingelsewhere, the relative orientation of the simulator can be assessedusing a tilt tracker and multiplying or otherwise mathematicallyremoving the actual orientation by the three desired rotations. RelatingS to desired Rs enabled the formation of the equations:S ₁₃ =A′R _(x) +B′R _(y) +C′R _(z)S ₃₂₁ =D′R _(x) +E′R _(y) +F′R _(z) S=f′(R)S ₁₄₃ =G′R _(x) +H′R _(y) +I′R _(z)

In conclusion, the three equations that show the required stimulations Sas a function of the desired rotations R are the inputs needed in orderto drive vestibular stimulation within a motion simulation system.Therefore, a desired motion (input) can be achieved by runningstimulation software embedded with these three equations in order tocommand stimulation of electrode sets in a specific pattern relative tothe equations' outputs.

There are also other embodiments of the present invention allowing formore than 3 motions up to as many as 6 motions. These other motions arepossible with additional equations. For example, Roll, Pitch, Yaw,Vertical, Forward/Backward, and Left/Right can be achieved as:

$\begin{bmatrix}S_{A} \\S_{B} \\S_{C} \\S_{D} \\S_{E} \\S_{F}\end{bmatrix} = {M^{\prime}\begin{bmatrix}R_{X} \\R_{Y} \\R_{Z} \\D_{V} \\D_{F} \\D_{L}\end{bmatrix}}$The M′ is the inverse of the 6×6 matrix that maps the 6 directions ofstimulation onto the six motions. Roll, pitch, and yaw are rotationaldirections and vertical (up and down), forward/back, and left/right arelinear directions. This adds up to 3 potential rotational directions and3 potential linear directions. The rotational directions are labeledwith R (Rx, R_(Y), and R_(Z)). The linear directions are labeled with D(D_(V), D_(F), and D_(L)). S within this equation is defined as thestimulations being applied within the present invention. The letter witheach S designates electrode sets. For example, A may be electrode set212, B may be electrode set 214, and so forth. As shown above, eachcollection of electrode sets has a matrix that stays constant with aspecific set of outputs R and/or D. The electrode set may then bestimulated at a specific level based on the input of the equations inorder to achieve a desired motion.

FIG. 8 is a schematic block diagram of one embodiment of a motionstimulation system 700. In general, the system 700 may be used tocoordinate stimulation through sets of electrodes on the human subjectwith visual or actual motion of the subject so as to affect thesubject's perception of motion. The visual motion is motion that thesubject perceives with their eyes, such as by seeing their surroundingsmove around them when they move, or when they are viewing a simulatedenvironment on one or more computer-controlled display devices 702. Theactual motion may be achieved by the subject 704 being on a platform,such as a moving vehicle, or a mechanically actuated platform such as ina simulator system. Thus, the system 700 may be implemented tocompensate for motion in an actual system such as an airplane or othervehicle, or in a simulator system such as a videogame or full scalesimulator such as a flight simulator.

Referring to particular components in FIG. 8, a human subject 704 isshown on a movable platform 706. The subject 704 has electrodes 708attached about their body, such as around their head in the mannerdiscussed above. The electrodes are connected to a current generator714, which is in turn connected to a central controller 716 in the formof a digital computer such as a personal computer or a vehicle computer.In implementations where the subject 704 is provided with simulatedmovements by the system 700, a motion controller 712 is connected to theplatform 706 by control lines 710 in order to move the platform in adesired direction at a desired speed. In addition, the computer 716 canbe connected to one or more video display devices 702 via videoconnectors 718.

The computer 716 is a central controller for the operation of the system700. The computer may initially receive input about motion for thesubject 704, which may include actual motion or simulated motion. Theseinputs are received from sensors 722 placed on the human subject. Inputsmay include measurements of orientation, speed, direction, observedmotion, and the like. The sensors send inputs along line 720 to thecomputer for further computation. For example, the subject 704 may movea yoke or other controller such as a joystick (whether wired orwireless) as part of an actual or simulated operation so as to bringabout a desired movement of the system. Such input may take familiarforms, either in an actual system or a simulator system. The computer716 may compute responses to the input from the subject 704 and maydisplay a result of the input on display devices 702, where the system700 is a simulator system.

The computer 716 may also determine parameters that must be provided interms of motion stimulation to the subject 704 so that the subject 704physically perceives an appropriate amount of motion or desired motion.These parameters may be determined through stimulation software within astimulation determination module (not shown) that may be embedded withinthe computer 716 and/or the current generator 714. This software mayalso be embedded with the various matrix equations discussed above.

For example, in a system 700 with motion platform 706 active (either bymotion of the floor or induced motion), the desire may be to cancel outall or some of the actual motion of the subject 704 in the platform 706so as to make the operation more comfortable for the subject 704. Insuch an environment, the desire may also be to change the subject'sperceived motion to some level other than what they would otherwiseperceive without intervention. In a system 700 where the motion platform706 is active or inactive, the aim may be to provide total perceivedmotion that matches and is coordinated with the visual motion on thedisplays 702, such as in a videogame system that does not have aplatform 706. Where a platform 706 is available, the aim may be to addperceived motion to the actual motion of the platform 706 so as to matchthe user's total perceived motion (actual plus induced perceived motion)with what they are seeing on the displays 702. The computer 716 can thussend appropriate signals to the motion controller 712 and the currentgenerator 714 so as to move the subject 704 to the extent possible tomatch the visual cues provided by the displays 702, and to addstimulation to compensate and provide an appropriate non-visual totalperception of motion to reach the desired goal.

Other additional or alternative features may also be provided with thesystem 700. For example, in addition or alternatively to providing thesubject 704 with a yoke or other controller for controlling displays 702and/or a platform 706, the subject may be provided with an inputmechanism for reporting perceived motion, such as reporting a level ofdiscomfort felt in response to receiving various stimulations. Suchinput may be used in studying the subject 704 to determine the subject'ssusceptibility to motion-related discomfort, and to determine whetherGVS stimulations being provided to the subject 704 are effective or needto be adjusted. In this manner, a GVS system for cancellingmotion-induced effects may be calibrated for the particular subject, andsettings suggested by such calibration may then be used with respect tothe subject. For example, those settings may be electronically stored,and then loaded the next time the subject appears for simulatortraining. Also, a portable stimulation system may be provided for peoplewho have motion sickness, where motion sensors (e.g., accelerometersand/or gyroscopes) may be placed in the portable device and may causestimulations to be provided to a subject to offset motion sensed by themotion sensors of an airplane or some other vehicle in which the subjectis located. For example, a portable box may be mounted to the subject'sbelt, and a cap or headband containing stimulation electrodes may beplaced over the subject's head.

FIG. 9 is a flowchart showing one embodiment of a method for usingmotion stimulation on a subject. In general, the process is directed toreceiving inputs about an actual motion of a subject, or a motion thatthe subject is perceiving or is to perceive visually. In a simulatorenvironment, such inputs will supplement any actual motion provided bythe process to the user, so as to better match their non-visualperception of motion with their visual perception of motion. The processincludes a step of receiving a motion of the subject and may alsoinclude a step of receiving a motion of the visual scene being displayedto the subject (802). An additional step may be receiving a controlinput from the user regarding desired movement in a certain directionand at a certain speed as specified by the user. Such an input, in areal system, may come from joysticks, accelerometers and/or othersensors mounted in a vehicle such as an airplane. With a simulator orother form of videogame, the input may come from a subject moving aninput mechanism like a yoke or handheld controller so as to move avehicle in which they are being simulated. Another step in the processis determining the orientation of a user's head (804). This means thatthe user's actual motion is determined based on the orientation of auser's head. As noted, the actual motion may come from outside thesystem where real activity is taking place, or may come from within thesystem where the process may control a platform, enclosure, chair, orother similar device in which the user has been placed on or within. Inthe latter situation, the movement of the platform or enclosure may beinsufficient to match the user's non-visual perception of motion to theuser's visual perception of motion.

The process also includes a step of determining a needed level ofperceived non-visual motion (806). In a typical situation, such adetermination may be made by determining the level of motion beingprovided visually to video displays in the system and subtracting acorresponding level of actual motion being provided to the subject by aphysical platform to which the subject is connected. The orientation ofthe subject's head may also be accounted for. Such comparison andcomputation may be completed by conventional mechanisms. The computationmay occur in a computer that runs the simulation or in a specializedcontroller directed to provide stimulations that create perceivednon-visual motions in order to match perceived visual motionsappropriately.

Another part of the process is the step of computing a stimulus neededto generate a level of perceived non-visual motion (808). Thus forexample, during the step of determining a level of perceived motion(806), it may be determined that the user needs to be provided with aperception of rotation through 90 degrees over 1 second. It may befurther determined that a platform can provide half of that perception.Thus a 45 degree input may need to be provided to the user to matchtheir perceived non-visual motion with the perceived visual motion(e.g., provided by video monitors). The step of computing a stimulus(808) may use the techniques above to determine the level of stimulationand the stimulation profile over time that is needed to provide suchperception. In certain situations, the needed perceived non-visualmotion may not need to match the perceived visual motion, such as whenit is impossible to match the two. In such a situation, a best practicalsimulated non-visual motion may be determined, and stimulation may beprovided to give the subject such a perception of motion.

The process also includes a step of generating stimuli and transmittingthe stimuli to the subject, such as over leads to multiple sets ofelectrodes placed on the subject as described above. The stimuli maytake an appropriate profile such as a ramped step signal havingappropriate ramp angles, as discussed above, and that profile can berepeated over time, such as over a time during which the subject'sperception is to be simulated. For example, if the subject is simulatinga long (e.g., several seconds) banking action in an airplane, thestimulations needed to achieve a non-visual perception of that actionmay be delivered repeatedly to the subject during the banking procedurein coordination with video signals that show the view out of an airplanewith the occurrence of a correlated banking procedure.

Example 4 Alleviating Simulator-Related Sickness

Use of GVS in mitigation of nausea and dizziness associated withsimulator sickness and motion sensitivity was tested. An entireelectrode montage for the head was applied to each of 30 testsubjects—with half receiving actual GVS per the equations describedabove, and half receiving sham stimulations (no GVS). Each subject wasseated in a replica of an actual flight seat as part of a simulator, andpositioned before a video display. Each subject was given the sameinstructions. A series of inputs designed to cause most, if not all,subjects to experience some level of stimulator sickness was thenexecuted. For the first 5 minutes, the visual field responded asexpected to the control inputs. After this initial acclimation period,the input from the throttle was automatically modified by a sinusoid at4 Hz, with amplitude from 0.5 to 5 times the user commanded motion. Forexample, if the subject commanded a constant turn in yaw at 30degrees/second, after the acclimation period, the speed of this turnwould vary between 15 degrees/second to 150 degrees/second. A visualflow field (white dots on a black background) was displayed in order toeliminate subjectivity that may arise with complex visuals. The controlsincluded a joystick (controlling pitch and roll), throttle (controllingspeed), and foot pedals (controlling yaw).

Subjects were trained to move in all axes. The tests were run for a timeequal to the shortest of (a) 20 minutes; (b) as long as the subjectwished; and/or (c) based on a determination by the test administratorthat the subject was in distress. Symptoms of simulator sickness werereported by the subject and were assessed by the test administrator onvisual analog scales that ranked from 0 to 10. Symptoms included suchailments as drowsiness, pallor, vomiting, dizziness, sweats, nausea,headaches, warmth, salivation, and other related symptoms. The data wastabulated for each symptom from the visual analog scale for bothself-reported and observed symptoms. The averages indicate a score ofapproximately 4.2 for sham subjects and 2.8 for subjects who hadreceived actual GVS. All symptoms were scored by the subjects or testadministrator on a scale from 0 to 10, with higher numbers indicating ahigher severity. For example, a score of 4 was always “worse” than ascore of 2. Although the highest individual score was 10, no symptom hadan average score greater than 5. Based on the bar graphs in FIGS. 10A-B,there was a marked decrease in dizziness, nausea, and sweating, althoughthere was a slight increase in drowsiness when GVS was applied. FIG. 10Cpulled apart the nausea scores for all 23 subjects that were able to berecorded since this symptom is most directly relevant to simulatorsickness.

As shown in FIGS. 10A-C, the self-reported and observed scoresdemonstrate a consistent pattern, with the following trends noted inusing the GVS-coupled simulator: (1) marked decrease in average nausea,dizziness, sweat, and warmth, which are all symptoms of motion sickness;(2) both the incidence and severity of nausea decreased; and (3) aslight increase in drowsiness was noted. The incidence of nauseadecreased from 8 of 12 sham subjects (67%) to 4 of 11 GVS subjects(36%). Moreover, when nausea was reported, the median value decreasedfrom 6 to 2.5. Therefore, the present invention decreased both theincidence (67% to 36%) and severity (6 to 2.5) of the nausea. This meansthat fewer people overall were getting nauseated and the severity ofnausea felt by people decreased with the GVS application.

The GVS applied in this example uses the same setup described above forthe simulator. By using GVS to induce vestibular motion sensations thatmatch the visual field, the incidence and severity of motion-relatedsymptoms associated with the simulator were reduced.

Example 5 Computer and Electrical Components

FIG. 11 shows one embodiment including a generic computing device 1000and a generic mobile computer device 1050, which may be used with thetechniques described herein. Computing device 1000 is intended torepresent various forms of digital computers, such as laptops, desktops,workstations, personal digital assistants, servers, blade servers,mainframes, and other appropriate computers. Mobile computer device 1050is intended to represent various forms of mobile devices, such aspersonal digital assistants, cellular telephones, smartphones, and othersimilar computing devices. As one example, computing device 1000 may beused to operate a simulation system, to receive inputs, and provide GVSstimulations coordinated with an ongoing stimulation. This system wouldbe capable of reducing simulator sickness in a subject or match totalperceived motion for a subject to a visual perception of motion that thesubject is undergoing. Mobile computer device 1050 may be a portabledevice that can be used to provide GVS so as to reduce motion sickness,such as in a commercial airline passenger. The components shown here,their connections and relationships, and their functions, are meant tobe exemplary only, and are not meant to limit implementations of theinventions described and/or claimed in this document.

Computing device 1000 includes a processor 1002, memory 1004, a storagedevice 1006, a high-speed interface 1008 connected to memory 1004,high-speed expansion ports 1010, and a low speed interface 1012connected to a low speed bus 1014 and storage device 1006. Each of thecomponents 1002, 1004, 1006, 1008, 1010, and 1012 are interconnectedusing various busses, and may be mounted on a common motherboard or inother manners as appropriate. The computing device 1000 may also includea stimulation generator card 714 connected directly to the low speed bus1014 or the high speed interface 1008. The stimulation generator 714outputs to a set of electrodes 708. The stimulation generator 714 sendsa certain amount of electrical signals to the electrodes 708. Thestimulation generator 714 may also include a stimulation determinationmodule embedded within the generator card 714 or the module may beembedded within the processor 1002. This module is used for computingthe amount of needed stimulation to be sent to electrodes 708 by thestimulation generator 714. The processor 1002 can process instructions(such as stimulation of electrodes) for executing within the computingdevice 1000, including instructions stored in the memory 1004 or on thestorage device 1006 in order to display graphical information for a GUIon an external input/output device, such as display 1016 coupled to highspeed interface 1008. In other implementations, multiple processorsand/or multiple buses may be used, as appropriate, along with multiplememories and various types of memories. Also, multiple computing devices1000 may be connected, with each device providing portions of thenecessary operations (e.g., as a server bank, a group of blade servers,or a multi-processor system).

The memory 1004 stores information within the computing device 1000. Inone implementation, the memory 1004 is a volatile memory unit or units.In another implementation, the memory 1004 is a non-volatile memory unitor units. The memory 1004 may also be another form of computer-readablemedium, such as a magnetic or optical disk.

The storage device 1006 is capable of providing mass storage for thecomputing device 1000. In one implementation, the storage device 1006may be or contain a computer-readable medium, such as a floppy diskdevice, a hard disk device, an optical disk device, a tape device, aflash memory or other similar solid state memory device, or an array ofdevices, including devices in a storage area network or otherconfigurations. A computer program product can be tangibly embodied inan information carrier. The computer program product may also containinstructions that, when executed, perform one or more methods, such asthose described above. The information carrier is a computer-readable ormachine-readable medium, such as the memory 1004, the storage device1006, memory on processor 1002, or a propagated signal.

The high speed controller 1008 manages bandwidth-intensive operationsfor the computing device 1000, while the low speed controller 1012manages lower bandwidth-intensive operations. Such allocation offunctions is exemplary only. In one implementation, the high-speedcontroller 1008 is coupled to memory 1004, display 1016 (e.g., through agraphics processor or accelerator), and to high-speed expansion ports1010, which may accept various expansion cards (not shown). In oneimplementation, low-speed controller 1012 is coupled to a storage device1006 and a low-speed expansion port 1014. The low-speed expansion port,which may include various communication ports (e.g., USB, Bluetooth,Ethernet, wireless Ethernet) may be coupled to one or more input/outputdevices, such as a keyboard, a pointing device, a scanner, or anetworking device such as a switch or router, e.g., through a networkadapter.

The computing device 1000 may be implemented in a number of differentforms, as shown in FIG. 11. For example, it may be implemented as astandard server 1020, or in a group of such servers. It may also beimplemented as part of a rack server system 1024. In addition, it may beimplemented in a personal computer such as a laptop computer 1022.Alternatively, components from computing device 1000 may be combinedwith other components in a mobile device (not shown), such as device1050. Each of such devices may contain one or more of computing devices1000, 1050, and the entire system may be made up of multiple computingdevices 1000, 1050 communicating with each other.

Mobile computing device 1050 includes a processor 1052, memory 1064, aninput/output device 1054 such as a display and/or electrodes, acommunication interface 1066, and a transceiver 1068, among othercomponents. The device 1050 may also be provided with a storage device,such as a microdrive or other device, to provide additional storage.Each of the components 1050, 1052, 1064, 1054, 1066, and 1068, areinterconnected using various buses, and several of the components may bemounted on a common motherboard or in other manners as appropriate.

The processor 1052 can execute instructions within the mobile computingdevice 1050, including instructions stored in the memory 1064. Theprocessor may be implemented as a chipset of chips that include separateand multiple analog and digital processors. The processor may provide,for example, for coordination of the other components of the device1050, such as control of user interfaces and electrodes, applicationsrun by device 1050, and wireless communication by device 1050.

Processor 1052 may communicate with a user through control interface1058 and display interface 1056 coupled to the input/output device 1054.The input/output device 1054 as a display may be, for example, a TFT LCD(Thin-Film-Transistor Liquid Crystal Display) or an OLED (Organic LightEmitting Diode) display, or other appropriate display technology. Thedisplay interface 1056 may comprise appropriate circuitry for drivingthe display 1054 to present graphical, electrical, and other informationto a user. The control interface 1058 may receive commands from a userand convert them for submission to the processor 1052. This controlinterface 1058 may also be a stimulation generator when the input/outputdevice 1054 is a set of electrodes. The stimulation generator sends acertain amount of electrical signals to the electrodes. There may alsobe a stimulation determination module embedded within the stimulatorgenerator and/or within the processor 1052. This module is used forcomputing the amount of needed stimulation to be sent to electrodes. Inaddition, an external interface 1062 may be provided in communicationwith processor 1052, so as to enable near area communication of device1050 with other devices. External interface 1062 may provide, forexample, for wired communication in some implementations, or forwireless communication in other implementations, and multiple interfacesmay also be used.

The memory 1064 stores information within the mobile computing device1050. The memory 1064 can be implemented as one or more of acomputer-readable medium or media, a volatile memory unit or units, or anon-volatile memory unit or units. Expansion memory 1074 may also beprovided and connected to device 1050 through expansion interface 1072,which may include, for example, a SIMM (Single In Line Memory Module)card interface. Such expansion memory 1074 may provide extra storagespace for device 1050, or may also store applications or otherinformation for device 1050. Specifically, expansion memory 1074 mayinclude instructions to carry out or supplement the processes describedabove, and may include secure information as well. Thus, for example,expansion memory 1074 may be provided as a security module for device1050, and may be programmed with instructions that permit secure use ofdevice 1050. In addition, secure applications may be provided via theSIMM cards, along with additional information, such as placingidentifying information on the SIMM card in a non-hackable manner.

The memory may include, for example, flash memory and/or NVRAM memory,as discussed below. In one implementation, a computer program product istangibly embodied in an information carrier. The computer programproduct contains instructions that, when executed, perform one or moremethods, such as those described above. The information carrier is acomputer-readable or machine-readable medium, such as the memory 1064,expansion memory 1074, memory on processor 1052, or a propagated signalthat may be received, for example, over transceiver 1068 or externalinterface 1062.

Mobile computing device 1050 may communicate wirelessly throughcommunication interface 1066, which may include digital signalprocessing circuitry where necessary. Communication interface 1066 mayprovide for communications under various modes or protocols, such as GSMvoice calls, SMS, EMS, or MMS messaging, CDMA, TDMA, PDC, WCDMA,CDMA2000, or GPRS, among others. Such communication may occur, forexample, through radio-frequency transceiver 1068. In addition,short-range communication may occur, such as using a Bluetooth, WiFi, orother such transceiver (not shown). In addition, GPS (Global PositioningSystem) receiver module 1070 may provide additional navigation- andlocation-related wireless data to device 1050, which may be used asappropriate by applications running on device 1050.

Mobile computing device 1050 may also communicate audibly using audiocodec 1060, which may receive spoken information from a user and convertit to usable digital information. Audio codec 1060 may likewise generateaudible sound for a user, such as through a speaker, e.g., in a handsetof device 1050. Such sound may include sound from voice telephone calls,recorded sound (e.g., voice messages, music files, etc.) and may alsoinclude sound generated by applications operating on device 1050.

The mobile computing device 1050 may be implemented in a number ofdifferent forms, as shown in FIG. 11. For example, it may be implementedas a cellular telephone 1080. It may also be implemented as part of asmartphone 1082, personal digital assistant, or other similar mobiledevice.

Various implementations of the systems and techniques described here canbe realized in digital electronic circuitry, integrated circuitry,specially designed ASICs (application specific integrated circuits),computer hardware, firmware, software, and/or combinations thereof.These various implementations can include implementation in one or morecomputer programs that are executable and/or interpretable on aprogrammable system including at least one programmable processor, whichmay be special or general purpose. The programmable processor may becoupled to receive data and instructions from, as well as transmit dataand instructions to, a storage system, at least one input device, and atleast one output device.

These computer programs (also known as programs, software, softwareapplications or code) include machine instructions for a programmableprocessor, and can be implemented in a high-level procedural and/orobject-oriented programming language, and/or in assembly/machinelanguage. As used herein, the terms “machine-readable medium” and“computer-readable medium” refers to any computer program product,apparatus and/or device (e.g., magnetic discs, optical disks, memory,Programmable Logic Devices (PLDs)) used to provide machine instructionsand/or data to a programmable processor, including a machine-readablemedium that receives machine instructions as a machine-readable signal.The term “machine-readable signal” refers to any signal used to providemachine instructions and/or data to a programmable processor.

To provide for interaction with a user, the systems and techniquesdescribed here can be implemented on a computer having a display device(e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor)for displaying information to the user. A set of electrodes in variousembodiments may also be implemented as an output device. A keyboard,pointing device (e.g., a mouse or a trackball) and orientation sensorsprovide the means for the user to provide input to the computer. Otherkinds of devices can be used to provide for interaction with a user aswell; for example, feedback provided to the user can be in any form ofsensory feedback (e.g., visual feedback, auditory feedback, or tactilefeedback); and input from the user can be received in any form,including acoustic, speech, or tactile input.

The systems and techniques described here can be implemented in acomputing system that includes a back end component (e.g., as a dataserver), a middleware component (e.g., an application server), or afront end component (e.g., a client computer having a graphical userinterface or a Web browser through which a user can interact with animplementation of the systems and techniques described herein), or anycombination of such back end, middleware, or front end components. Thecomponents of the system can be interconnected by any form or medium ofdigital data communication (e.g., a communication network). Examples ofcommunication networks include a local area network (“LAN”), a wide areanetwork (“WAN”), and the Internet.

The computing system can include clients and servers. A client andserver are generally remote from each other and typically interactthrough a communication network. The relationship of client and serverarises by virtue of computer programs running on the respectivecomputers and having a client-server relationship to each other.

A number of embodiments have been described. Nevertheless, it will beunderstood that various modifications may be made without departing fromthe spirit and scope of the invention. For example, much of the presentinvention has been described with respect to particular uses for GVS,but other applications and combinations of the above described presentinvention would also be addressed, as would be understood by a skilledartisan upon reviewing the description above.

In addition, the logic flows depicted in the figures do not require theparticular order shown, or sequential order, in order to achieve thedesirable results. In addition, other steps may be provided, or stepsmay be eliminated, from the described flows, and other components may beadded to, or removed from, the described systems. Accordingly, otherembodiments are within the scope of the following claims.

Example 6 Directional Cueing

Another embodiment of the present invention is use of GVS in providingdirectional cueing to an ambulatory subject. An entire electrode montagefor the head was applied to the subject as described above, and inputswere given based on the dose response as determined in Example 3. Targetlocations were chosen at random by the test administrator and then cueswere given to the subject to redirect the subject's vector towards thetargets. Cues included a speed and directional component. The subjectwas able to move forward, turn, and stop according to the GVS inputs.This technology allows for a subject to be moved to a precise targetwith the use of GVS.

The directional cueing may be embodied within a computer system ormobile computer system. This system may include a computer that receivesan input regarding motion of a subject. This input includes ameasurement of location and movement of the subject. The measurement mayfurther include direction and speed of the subject. The cueing systemmay also include a stimulation determination module that is connected tothe computer for computing an amount of stimulation to be provided tothe subject in order to direct the subject on a course to a specificlocation. The course may include a direction and speed component foreach step within the entire course. The system may also include acurrent generator that is connected to the determination module. Thegenerator sends electrical stimulations to the subject via electrodes inorder to physically move the subject at various speeds and directions toend at the specific location. There is also a set of electrodes,preferably two distinct sets of electrodes, located on the subject forcausing stimulation of the subject to move at a speed in a certaindirection.

This system includes a process for providing directional cueing. Theprocess may include a step of receiving an input that includes thedirection and speed of a subject's motion. This process may also includea step of determining a course required to direct a subject to aspecific location. Another step may be determining an amount ofstimulation required to cause the subject to take the course to thespecific location desired. The stimulation is related to input from theuser as to speed and direction. There may also be another step ofdelivering stimulation to sets of electrodes that are contacting thesubject in order to cause the subject to move in the desired directionand speed.

Other Embodiments

Other embodiments will be evident to those of skill in the art. Itshould be understood that the foregoing detailed description is providedfor clarity only and is merely exemplary. The spirit and scope of thepresent invention are not limited to the above examples, but areencompassed by the following claims. The contents of all referencescited herein are incorporated by reference in their entireties.

Modifications and substitutions by one of ordinary skill in the art areconsidered to be within the scope of the present embodiments, which arenot to be limited except by the following claims.

The invention claimed is:
 1. A computer-implemented method for motionstimulation or treating motion sickness, the method comprising:receiving an indication of a sensed motion experienced by the humansubject; determining an activation pattern of electrical stimulationsignals of differing values applied to different locations on anexterior of a head or neck of the human subject needed for non-visualmotion perceived by the human subject to match the sensed motion;generating the activation pattern of electrical stimulation signals ofdiffering values applied to different locations on the exterior of thehead or neck of the human subject; and providing at least three distinctsets of electrodes responsive to said activation pattern of electricalstimulation signals of differing values applied to the differentlocations on the exterior of the head or neck of the human subjectconfigured to provide the human subject with a non-visual perception ofmotion in at least three separate directions that are coordinated withthe sensed motion.
 2. The method of claim 1 wherein the at least threeseparate directions further comprises roll, pitch, and yaw.
 3. Themethod of claim 1 wherein the at least three separate directions isselected from the group consisting of roll, pitch, yaw, up/down,right/left, and forward/backward.
 4. The method of claim 1 furthercomprising providing on one or more video display devices configured todisplay the sensed motion experienced by the human subject.
 5. Themethod of claim 4 wherein determining the activation pattern ofelectrical stimulation signals comprises identifying a level ofnon-visual motion to match the display corresponding to the motion onthe video display devices, and identifying a level of galvanicvestibular stimulation adequate to produce a sensation substantiallycorresponding to a level of needed motion-related stimulation.
 6. Themethod of claim 1 wherein the indication of sensed motion experienced bythe human subject is received in response to the human subject providingan input to produce simulated motion with a sensing unit.
 7. The methodof claim 6 wherein the sensing unit is part of a steering assembly for asimulated vehicle.
 8. The method of claim 1 wherein determining theactivation pattern of electrical stimulation signals comprisesidentifying a level of non-visual motion to counteract simulatorsickness created by the motion experienced by the human subject, andidentifying a level of galvanic vestibular stimulation adequate toproduce a sensation substantially corresponding to a level of neededmotion-related stimulation.
 9. The method of claim 1 wherein theactivation pattern of electrical stimulation signals comprise DC signalsof differing values applied to different locations around the subject'shead.
 10. The method of claim 9 wherein the DC signals of differingvalues comprise repeated periodic DC stimulations, wherein at least twoelectrodes at different locations around the subject's head receivestimulations of substantially equal amplitude.
 11. The method of claim 1wherein generating activation pattern of electrical stimulation signalsto the sets of electrodes in contact with the human subject alleviates amotion-related sickness.
 12. The method of claim 11 wherein themotion-related sickness is selected from the group consisting ofdrowsiness, pallor, vomiting, dizziness, sweat, nausea, headache,warmth, and salivation.